KENNEDY SPACE CENTER, FLA. - On Launch Complex 17-A, Cape Canaveral Air Force Station, the Boeing Delta II rocket and its Mars Exploration Rover (MER-A) payload are free of the tower (right) and ready for launch. This will be the third launch attempt in as many days after weather concerns postponed the launches June 8 and June 9. MER-A is the first of two rovers being launched to Mars. When the two rovers arrive at Mars in 2004, they will bounce to airbag-cushioned landings at sites offering a balance of favorable conditions for safe landings and interesting science. The rovers see sharper images, can explore farther and examine rocks better than anything that has ever landed on Mars. The designated site for MER-A mission is Gusev Crater, which appears to have been a crater lake. The second rover, MER-B, is scheduled to launch June 25.